Process for making abrasive articles



July 26, 1932. E. D. vANcE PROCESS FOR MAKING ABRASIVE ARTICLES Filed May 19. 1930 ATToRNEYS Patented July 26,` 1932 UNITED STATES PATENT OFFICE EDWARD D. VANCE, OF SPRINGFIELD; 013110,. ASSIGNOR TO Y'IIEE SAFETY GRINDING WHEEL & MACHINE COMPANY, 0F SPRINGFIELD, OHIO, A CORPORATION OF OHIO 1 PROCESS FOR MAKING ABBASI'V'E ARTICLES Application led May 19, 1930. Serial No. 453,626.

My invention relates to improvements in abrasive articles and particularly to grinding wheels. Abrasive articles such as grinding wheels have been made with various granular substances with different kinds of binders. One of the most common forms is what is known as vitritied or silicate wheels in which the granular material such as emery or carborundum, etc., is bound together by silicate binders which when baked at a proper temperature forms a porous substance consist-ing of the granular elements held together by the binder which is more or less solidiied.

It has also been the practice to supply these porous wheels when desired with an auxiliary binder such as synthetic resin, shellac and the like. plied to the porous articles by dipping the wheel or other article into a liquid solution of the particular substance which makes up the auxiliary binder and afterwards allowing itto properly set, preferably by the application` of heat.

Considerable difficult-y has been experienced in obtaining a wheel of uniform texture with a supplemental binder by the methods heretofore employed a's the supplemental binder in liquid form will change its position in the porous substance before it is propv erly set and a portion of it will escape through the pores so as to leave the article in an un-` balanced condition or with some of the pores completely filled and others only partially filled with the liquid binder. A

To overcome these diiculties I have .de-

signed a vprocess by which the articleis uniformly filled andthe liquid properly maintained in the pores'until the supplemental 1y setting cement and then applying the supplemental binder in liquid forrn'to the uncoated side until all the pores are complete- These supplemental binders are apr ly filled and usually with an excess of the material on the uncoated side.

When synthetic resin and similar substances are used as lan auxiliary binder the article so impregnated is maintained in an upright position or in the position in which the uncoated side is at the top and the same is then inserted into a suitable kiln where it is heated to the proper temperature to com- 4 pletely set the auxiliary binder or change it into a hard tough supple'mental bond.

After the supplemental binder has thus been treated the article is removed from the kiln and the outer covering of cement which 'material on the uncoated side of the article is then removed by 'ya process of dressing which in the case of wheels would consist in ,supporting the 'wheel in a proper position and with proper tools removing the surplus material and the outer coating.

Wheelsthus treated it has been found in practice have a more perfect supplemental inder and a completel homogeneous mass and with a supplementalybinder which is uniform throughout thus making a perfectly balanced wheel or .other article and also much stronger than when the supplemental binder is applied by dipping or otherwise.

In the' drawing attached thereto:

Fig. 1 is a plan view of a Wheel to which the outer coating of cement has been applied and in a osition to receive the liquid supplementa binder.

Fig. 2 is a cross section of the same.

In these figures, 1 represents the porous wheel or other article and'2 a coating of cement around the periphery and the bottom of the wheel and also the sides of the openings 3 which ordinarily extend through the center of a grinding wheel.

For coating the sides and periphery of this wheel to stop the pores to prevent the leakageof the liquid binder I use any suitable cement preferably one which will stand the temperature of baking Where synthetic resin and similar substances are employed for the auxiliary binder. Air drying cement such as Portland cement or suitable forms of clay 2 A l :,seaosi cement may be used. I have very successfull used a commercial cement under the tra e-name Sair Set Cement.

Having thus described -my invention, I claim:

1. The process of applying a supplemental binder to a porous abrasive article which consists in` coating such article on` all its sides except one with a pore stopping cement, ap-

lying said suppplemental binder in a liquid orm to the uncoated side of said article until all the pores are uniformly filled, retaining the article in the position in which the liquid binder is applied until it has properly Iand permanently set and then removing the outer pore stopping covering and the surplus binding material.

2. The process of applying a supplemental binder to abrasive artic es formed o a porous material which consists in a plying a temporary quickly setting coverlng which will stop the pores on all the sides of said article except one, applying a supplemental binder in liquid form to the uncoated side of said article, retaining the same in the position in which the liquid is applied and subjecting the same to heat in the same position until the binder is completely and permanently set and then removing the outer cover and the surplus material.

3. The process of making an abrasive wheel which consists in applying to a vitrifed or other porous Wheel a coatm of air drying cement on all the surfaces osaid wheel ex-v cept one, applying a liquid supplemental A binder to the uncoated s1de, subjecting the article to heat to permanently set the supplemental binder and thereafter removing the pore stopping'eoatin and surplus binder from the sides and perip ery of the Wheel.

4. The process o applying a supplemental binder in liquid .form to a porous abrasive article which consists in coating the major portion of such article with a covering impervious to the binder, applying such supplemental binder to the exposed portion of such article, and removing the outer covering after the binder has set.

5. The process of applying a supplemental binder in liquid form to a porous abrasive article which consists in coating the major portion of such article with a covering impervious to the binder and of a character to resist heat sufficient to set the binder, applying the liquid binder to the exposed ortion of said article, then setting the same y heat and thereafter removing the covering.

In testimony whereof, I have hereunto set o my hand this 15th day of May, 1930.

EDWARD D. VAN CE. 

